Bristle branching blade



June 29, 1965 H. c. PETERSON 3,

BRISTLE BRANCHING BLADE Filed June 28, 1962 1 gfwmld CPeins'm W, 7% 5 United States Patent 3,191,478 BRISTLE BRANCHING BLADE Harold C. Peterson, Geneva, Ill., assignor to Carlson Tool & Machine Company, a corporation of Illinois Filed June 28, 1962, Ser. No. 205,940 2 Claims. (Cl. 83-663) This invention relates to a bristle conditioner such as a bristle branching machine, and more particularly to a blade structure thereof.

The use of many different bristle materials has become increasingly prevalent in various types of brushes, and particularly in paint brushes, Such bristle materials include synthetic materials as well as natural bristle materials, and all have numerous advantages. For example, nylon bristles are very durable and require little care, but they inherently lack liquid holding power so that paint or other liquid easily flows off of such bristles. To overcome this difiiculty, the free ends of nylon bristles have been treated in various manners including splitting the end of each bristle to provide a branch-like'structure, thus substantially increasing the paint-holding capacity of the brush and softening its end. Other bristle materials which may be branched in a manner similar to nylon bristles include other synthetics such as polyvinyl chloride and polyvinylidene chloride, and natural fiber such as horsehair.

A popular method of branching the ends of such bristles, whether the bristles are bundled or assembled in a brush, involves the use of a rotary blade assembly having blades each with diametrically opposed sharp points which pierce and split the bristle ends to provide a branched end structure. In addition to having sharp points for piercing individual bristles, these blades also have sharp edges extending from the points for facilitating cutting through the bristles to form crotches of the branches, and rounded edges extending from the points inwardly of the sharp edges for longitudinally splitting the bristle ends. In order to properly branch such bristles, the blades must be maintained very sharp, and during normal operation they must often be sharpened, usually every day or two. Since each branching machine is equipped with a plurality of blades, the necessity for maintaining the blades in adequate sharpness is a time consuming and expensive operation, particularly because of complex assembly of the blades into a rotary cutting unit, and the required shape of blades previously necessary to provide proper branching made sharpening difficult. These prior blade shapes also require expensive manufacturing techniques.

The primary object of this invention is to provide a new and useful brush branching machine, and components thereof. i 1

An important object is to provide anew and useful blade assembly and components thereof for a bristlebranching machine.

Another object is to .provide a new and useful branching machine blade assembly which may be easily dismantled and assembled,

A more specific object is provision of a new and useful blade assembly for a bristle branching machine including a series of blades, and washers telescoped on'a shaft between the blades to space the blades axially of the shaft, with rods telescoped through aligned openings in the blades and washers to hold the blades in assembly, and means on opposite ends of the shaft retaining the rods, washers and blades in operative assembly.

A further object is provision of a new and useful branching blade which is simple and economic to manufacture.

Another object is provision of .a new and useful branching blade having opposed branching portions.

3,191,478 Patented June 29, 1965 Still another object is provision of a new and useful rotary branching blade having a straight knife edge.

A. further object is provision of a new and useful brush branching machine blade which may be easily installed in and removed from a blade assembly.

A more specific object is provision of a new and useful rotary bristle branching blade having a leading edge portion with a sharp point and extending therefrom in the same general direction a knife edge and a rounded edge, the knife edge being substantially straight to facilitate easy and less expensive manufacturing and sharpening.

Additional objects and advantages of the invention will be apparent from the following description taken in con junction with the drawings, in which:

FIGURE 1 is a perspective view of a brush branching machine with parts broken away to more clearly illustrate a preferred embodiment of the invention in the form of a rotary blade assembly;

FIGURE 2 is a fragmentary longitudinal sectional view taken generally along the line 2-2 of FIGURE 1;

FIGURE 3 is a transverse sectional view taken generally along the line 3-3 of FIGURE 1;

FIGURE 4 is an enlarged side view of a preferred embodiment of a branching blade of the invention, removed from the machine;

FIGURE 5 is a fragmentary sectional view taken generally along the line 5-5 of FIGURE 4; and

FIGURE 6 is a side view, to a reduced scale, of another embodiment of a branching blade, removed from the machine.

While I have shown and shall hereinafter describe embodiments of the invention, it is to be understood that the invention is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The invention is, in brief, directed to a blade and blade assembly of a bristle conditioning machine. The blade assembly includes a rotary shaft removably mounted in journals and carrying a plurality of easily detachable bristle branching blades. In the illustrated embodiments series of these blades are spaced about the shaft. Washers are telescoped on the shaft and received between the blade of each series to space the blades axially of the shaft. Aligned holes in the washers and blades telescopically receive rods for releasably holding the blades in operative assembly. Clamping means, in the form of discs and nuts on either end of the shaft, are tightened against the series of washers and blades to hold the blades tightly clamped in assembly, and the discs overlie the rod ends to retain the rods in .their respective aligned holes. Each blade has a leading sharp point, and extending therefrom are a straight knife edge and a smooth edge, for piercing and slitting any bristles which are susceptible to branching, such as those previously mentioned.

Referring to the drawings, a bristle conditioning machine for branching bristles includes a body 10 carrying supports 11 mounting a rotary bristle branching blade assembly 12. Body 10 further has a housing 13 with a slot 14 across its top and partially down its sides for receiving'bristles 15a of a brush 15b mounted in a suitable holder (not shown) for movement through the slot and longitudinally of the blade assembly, as indicated by the arrow in FIGURE 1. In its illustrated and preferred form the machine is adapted for use in branching assembled brushes which have previously been trimmed, thus avoiding subsequent removal of a portion of the branched structure as by subsequent trimming, but the invention is also applicable .to branching of bundles of bristles prior to assembly into a brush.

Blade assembly 12 includes a rotary shaft 16 having opposite end portions removably mounted in removable cap journals 17 of supports 11 for easy insertion and removal of the blade assembly from the machine body. Means is provided for rotating blade assembly 12 about the longitudinal axis of its shaft 16, and herein this means is in the form of a pulley 18 mounted on one end of shaft 16 and receiving a drive belt 19 from a suitable source of power (not shown).

A plurality of bristle branching blades 2d are operatively carried by shaft 16, and in the illustrated embodiment means is provided mounting these blades on the shalt to provide a plurality of series of blades, here four series, equally spaced about the shaft, and the blades of each series spaced apart along the longitudinal axis of the shaft. As illustrated, this means includes a series of spacer members in the form of flat washers 21 snugly telescoped on shaft 16 with each adjacent pair of washers 2]; receiving a blade 2%? of each series therebetween. In the illustrated embodiment blades are equally spaced about the shaft axis between adjacent washer faces, thus maintaining the washers in firm assembly generally normal with respect to the longitudinal axis of shaft 16. Each series of blades is retained between the washers by pairs of rods 22 snugly received in aligned holes 23 in the washers and blades. The washers and blades are tightly clamped together and the rods are retained operatively assembled by means herein the form of clamping discs 24 received on either end of shaft 16 and overlying the ends of rods 22 to retain the rods in assembly, with nuts 25 threaded on the ends of the shaft ends and tightly clamping the discs against the series of washers and blades.

Blade assembly 12 may be easily removed from machine body lit? by removing the journal caps of supports 11 and belt 19 where upon the blade assembly may be lifted from its mounting. By merely removing one of the nuts 25 and adjacent disc 24 the rods 22 may be withdrawn and the blades 2d removed from between the washers. When installing the blades, the rods 22 are merely inserted through aligned holes 23, disc 24 is telescoped on shaft 16 and tightened against the adjacent end washer 21 by means of nut 25 to clamp the washers and blades together and retain rods 22 in place.

Blade assembly 12 may then be reinserted in its'journal, the journal cap replaced, and belt 19 engaged with pulley 18 so that the machine is ready for operation.

Each blade 29 has a body 26 in which holes 23 are provided for receiving rods 22 in mounting the blades for rotation about the longitudinal axis of shaft 16. Each blade has a leading edge portion 27 and a trailing edge portion 23. Leading edge portion 27 includes a sharp point 29 at the outermost region of the blade when it is operatively mounted on the shaft, and this point defines a circular path 3d upon rotation of the blade. A very sharp straight knife edge 31 extends from point 29 slightly inwardly of circular path 36 in a direction toward the shaft axis and toward trailing edge portion 28. As the blade rotates its point 29 pierces a bristle and knife edge 31 slightly cuts the bristle in a direction to form a crotch toward the bristle base in the handle of the brush. When the point 29 pierces a bristle it causes the bristle to be pulled in the direction of travel of the point which, in FIGURE 4, would be to. the right. In order to split rather than cut the bristle, leading edge portion 27 has a smooth rounded edge with a portion 32 extending from point 29in the same general direction as knife edge 31 and inwardly of the knife edge. In the illustrative embodiment this portion of the rounded edge is straight so as to tear the bristle in the direction of the bristle grain. Thus as the bristle is pulled outwardly it is also pulled slightly downwardly under the ripping influence of the leading edge. This places the bristle in a position where it may be contacted by the knife edge 31 so that the knife edge can cut the bristles toward the bristle base to form the crotch therein. This rounded edge has another portion 33 extending inwardly from straight portion 32 and Cit generally toward shaft 15, and connected with straight portion 32 by a concave curved portion 34. Trailing edge 28 has an outer portion 35 convexly curved and tangential toknife edge 31 to provide a smooth configuration devoid of sharp corners which might damage the branched bristle.

It should be noted that curved portion 34 of leading edge portion 27 is inwardly of the trailing portion of knife edge 31. Knife edge 31 defines an included angle of about 95 in a direction facing point 29, this angle being between edge 31 and a radius through the shaft axis and tangential to curved portion 34 of leading edge 27. The straight portion 32 of rounded edge 27 defines an included angle of about 20 with knife edge 31. These specific relationships may vary somewhat, but are preferred in that they have been found to provide substantially improved branching operations.

In FIGURE 6 a bristle branching blade 29' is illustrated, and similar parts are indicated by the same refer ence numerals as applied to blade 20. Blade 20 is generally similar to previously described blade 20, but has a novel Z-shaped configuration provided in part by generally diametrically opposed branching portions, each including a sharp point 29 and extending therefrom a sharp straight knifed edge 31, and a leading edge 27 and trailing edge 28, all as previously described. Blade 26' is so constructed that leading edge 27 of one branching portion intersects trailing edge 28 of the other branching portion to provide a generally Z-shaped configuration. The blade is rotatable in one direction about an axis de fined by the center of a circular hole 40 centrally located in the blade body between the branching portions. Hole 49 telescopically receives shaft 16 when the blade is assembled in a rotary blade assembly, as 12. This embodiment of the blade may be operatively assembled in any suitable or conventional manner to provide a rotary blade assembly. Blades 20 may be assembled in staggered series, generally in the manner illustrated in FIGURE 2, clamped between nuts 25 and spaced apart by washer 21 or in facial abutment with each other. In either embodiment, the provision of washers, as 21, facilitate easily varying the axial spacing between the branching portions by adding or removing washers, or substituting washers of suitable thickness, and blades 26 may facially abut each other. In the illustrated form, blade 20 is adapted to be clamped between nuts 25 and is provided with diametrically opposed pairs of holes 23 for receiving rods 22, as previously discussed.

By providing but one branching portion on each blade, manufacturing costs are appreciably reduced, and assembly of the rotor is simplified, as previously discussed. Should a blade point, as 29, or a knife edge, as 31, be damaged, replacement cost is reduced over that of double ended blades, and sharpening of a straight knife edge is less time consuming and expensive than sharpening of the old curved blades. However, the double ended blade is generally in keeping with industrially familiar type, but incorporates other features of applicants invention. V

I claim:

1. A rotary bristle branching blade, comprising: a body adapted for rotation about an axis; a straight blade edge at one end of the body, said edge having a leading portion with a sharp point therein defining an outermost circular path when said body is mounted for rotation about said axis, said blade edge describing a chord of the circular path defined by the rotation of said point at any one of an infinite number of positions of said blade in said path; and a rounded smooth edge extending from said point and inwardly of said blade edge into a curved portion directed generally toward said axis.

2. A rotary bristle branching blade, comprising: a generally flat elongate body having a centrally disposed opening for mounting said body about a rotatable axis; a straight blade edge at either end of said body, said edges being generally transverse to the longitudinal extent of said body; a leading portion on said edges, each leading portion having a sharp point defining an outermost circular path when said body is mounted for rotation about said axis, said straight blade edge describing a chord of the circular path defined by the rotation of said point at any one of an infinite number of positions of said blade in said path; and a rounded smooth edge extending from each point in a direction slightly inwardly of said circular path and smoothly into a sweeping curved portion directed generally toward said axis.

References Cited by the Examiner UNITED STATES PATENTS 2/02 Berger 146-1'21 6 1,348,751 8/20 Searby 146-121 1,583,150 5/26 Hind 146-121 1,744,597 1/ 30 Vasconcellos 30-347 X 2,039,677 5/36 Brooks 15-181 X 2,259,015 10/41 Anderson et a1 146-121 2,417,184 3/47 Wagner et al. 146-121 2,777,268 1/57 Breed 56-295 X FOREIGN PATENTS 1,043,990 6/53 France.

815,79 3 10/ 5 1 Germany. 93,769 4/59 Norway.

GRANVILLE Y. CUSTER, IR., Primary Examiner.

CHARLES A. WILLMUTH, Examiner. 

1. A ROTARY BRISTLE BRANCHING BLADE, COMPRISING: A BODY ADAPTED FOR ROTATION ABOUT AN AXIS; A STRAIGHT BLADE EDGE AT ONE END TOF THE BODY, SAID EDGE HAVING A LEADING PORTION WITH A SHARP POINT THEREIN DEFINING AN OUTERMOST CIRCULAR PATH WHEN SAID BODY IS MOUNTED FOR ROTATION ABOUT SAID AXIS, SAID BLADE EDGE DESCRIBING A CHORD OF THE CIRCULAR PATH 